For all the talk about a “post-PC” world, most people use smartphones or tablets as an addition to their existing technological arsenal, rather than a replacement for a standard laptop or desktop. In fact, there are a number of ways to combine the capabilities of your PC and mobile device that can make your tablet or smartphone an even more powerful tool. Last week, we took a look at an app that would let you use your iPad as a second monitor; this week, we'll talk about ways to use your iPad and iPhone as mobile file servers.

One of the useful features of the original iPod line was that the media players could also be used as external hard drives to transfer files between computers, a feature not to be discounted in those pre-Dropbox days. The iOS-equipped descendants of the iPod have shed those features, presumably to keep people from messing around with the devices' filesystems—iPhones, iPads, and iPod touches will be recognized as digital cameras by file explorers and most other programs, but you can't use them to move any old file around as you could with iPods of yore, at least not natively.

Luckily, apps exist to circumvent this limitation: there are a few, like Phone Disk, that will let you mount your iOS devices as external drives just as you could before, which is fine if you can install the client software on every computer you interact with, but what if you're trying to get your files on to a computer on which you don't have administrative access? In this case, turning your phone into a mobile file server makes it much easier to connect to from any computer.

Installing Air Sharing

For Android users: KFS or WiFi File Server

Android users can laugh all the way to the bank on this one: their phones typically can still be used as USB storage drives without issue, obviating the need for all of this tweaking if you just want to use your device to move files around. If making your phone into a simple file server still sounds like something you'd be interested in for convenience's sake, though, there are plenty of apps to do it, including kFS and WiFi File Server.

One of the most versatile mobile file server apps is Avatron's Air Sharing, an app which essentially turns your iPhone or iPad into a mobile file server. At $6.99 for the iPhone version, $7.99 for the iPad version, or $9.99 for a universal app, it's a little pricey, though there's nothing to prevent you from running the iPhone version on your iPad to save a few bucks as far as I can tell. Once purchased and set up, the app will let you use your device to move basically any type of file between computers and other devices running Air Sharing, either by connecting to the phone from a computer using WebDAV or Bonjour, or by connecting from the phone to a computer capable of running both SSH and SFTP (available natively in OS X and via third parties in Windows). Support for cloud storage servers like Dropbox, Box, and Google Docs is also included—directions for connecting to these various service and operating systems is included in the app's extensive documentation.

Uploading a file from a computer using Air Sharing. You can also mount the phone as a WebDAV server on any operating system that supports the protocol.

Starting up Air Sharing for the first time will show you an impressive and thorough list of documentation that will walk you through connecting to computers with Air Sharing, and connecting to your phone from just about every desktop OS and Web browser under the sun. Press "Done" to show the phone's file structure and expose the app's controls.

You can view your device's Bonjour name and IP address at any time by tapping the wireless icon.

The app is ready to use out of the box. Pressing the wireless icon at the bottom of the screen will show your phone's Bonjour name and IP address for your convenience. It doesn't require a password by default, so you'll probably want to go to Settings to change that before you start using it. Here, you can assign a username and password to be used when connecting to your "server," set a passcode to be entered when the app is launched (independent of the screen lock passcode), enable and disable access to the app's Public folder, and change the view settings for its file browser.

Mapping our Air Sharing "server" from Windows.

Once you've added a username and password, you can map the phone or tablet as you would any WebDAV server—the exact method varies from OS to OS, but the extremely thorough documentation lays it out in detail for you. Even more useful is Air Sharing's Web client, accessible by typing your device's IP address into any browser—you can easily download and upload files quickly and easily from any operating system.

Using Air Sharing's Web client is probably the easiest way to connect to your server from a computer you don't normally use, though it lacks the file explorer integration you get with WebDAV drive mapping.

Air Sharing's built-in file explorer can be used to create folders, import photos, and download webpages to your device.

The software has a few other caveats as well: for one, the app needs to be actively running on your phone or tablet for your computers to see it—if the phone goes to sleep or if you start using another app, Air Sharing will be suspended to save memory and your computers will lose their connection (in the app's settings, you can set it so that your device will never sleep while the app is running, though this is obviously done at the expense of battery life). Also, since the file transfers are happening over WiFi, your transfer speeds will typically be worse than they would be over USB. If these minor annoyances don't discourage you, your iPhone or iPad can make for a decent external drive in a pinch.

The Goodreader app does much the same things, plus it has a USB utility in addition to iTunes file transfer. Another bonus is that you can read large PDFs or preview images , movies, or text. The best part? It only costs 99 cents. Except the Goodreader app makes WiFi sharing a tap away vs always on. Meh, I think most people can live with a tap away anyway, especially if their IP address changes, they'll have to tap to get info anyway.

What's the point when you have services like drop box? I would understand this a bit more if iDevices could share their data, but doesn't sandboxing prevent the apps to share anything else than the data saved inside the app (camera rolls and few other sources excluded)? Both ways, drop box and this, require a additional SW installed to computer, but dropbox works even when the other recipient isn't running the app. What am I missing here?

edit. Just read from the comments above that Dropbox has a web interface too. That even emphasizes my point.

What's the point when you have services like drop box? I would understand this a bit more if iDevices could share their data, but doesn't sandboxing prevent the apps to share anything else than the data saved inside the app (camera rolls and few other sources excluded)? Both ways, drop box and this, require a additional SW installed to computer, but dropbox works even when the other recipient isn't running the app. What am I missing here?

Dropbox takes a long time to transfer large files. That's the reason USB drives still exist. Hence why why we need an app for USB or WiFi transfer, because most computers are unable to do it themselves at reasonably fast network speeds. Though it's a fair point to why not just carry around a USB drive? I think of the iPhone or iPad not as a main USB device, but backup in case I don't have one on me. But admittedly without a cable, transfer will be a lot slower (but faster than Dropbox).

What's the point when you have services like drop box? I would understand this a bit more if iDevices could share their data, but doesn't sandboxing prevent the apps to share anything else than the data saved inside the app (camera rolls and few other sources excluded)? Both ways, drop box and this, require a additional SW installed to computer, but dropbox works even when the other recipient isn't running the app. What am I missing here?

Dropbox takes a long time to transfer large files. That's the reason USB drives still exist. Hence why why we need an app for USB or WiFi transfer, because most computers are unable to do it themselves at reasonably fast network speeds. Though it's a fair point to why not just carry around a USB drive? I think of the iPhone or iPad not as a main USB device, but backup in case I don't have one on me. But admittedly without a cable, transfer will be a lot slower (but faster than Dropbox).

Right, and with Dropbox/Drive/other cloud storage solutions there are some privacy/storage space issues that can also be avoided with this method.

Odd. One of the features that drew me to my first "mega" mp3 play (creative vision:m) was that you could partition part of the 30gb hdd as an external drive. Better still, even in "player" mode, it was recognized as a mass storage device, and you could see all the folders and organize your music/vid collections as you saw fit. I guess that's an inconvenience for noobs that don't want to see any "scary" file management systems. But, doing away with this convenience in portable tech items seems like a slap in the face to techies.

AirDroid for android works nicely. Turn it on; phone opens up a little web server; connect to it in browser and you can remote control your phone; including sending text and root file system Not the same as a network mount; but near instant setup makes it extremely convenient for syncing tv shows/etc.

AirDroid for android works nicely. Turn it on; phone opens up a little web server; connect to it in browser and you can remote control your phone; including sending text and root file system Not the same as a network mount; but near instant setup makes it extremely convenient for syncing tv shows/etc.

As someone who spent a lot of time trying (and failing) to move some files (family photos) to/from his iPad last weekend, this piece comes a little too late.

Still, why I need a 3rd party tool, and can't have the iPad just represent itself (or part of itself) as a thumb drive to a host OS is still puzzling.

Use the data cable to plug your iPad into a windows pc without iTunes. It shows up like plugging in a digital camera, letting you drag and drop the pictures. I've never added pics, but have moved them off using this method. This method only shows you the photo folders however.

Much easier than using my wife's Macbook, that really really wants you to use that #$%^ iPhoto app. You can even download and install the windows iCloud control panel free and set images from your iOS devices photostream to download automatically, without buying an app like Mac users are required to do.

Exactly how useful is a file system app if you haven't jailbroken your iDevice? I mean can you actually access the device's system folders, or organize all your critical files into one folder and launch whatever program you want to view those files with?

What's the point when you have services like drop box? I would understand this a bit more if iDevices could share their data, but doesn't sandboxing prevent the apps to share anything else than the data saved inside the app (camera rolls and few other sources excluded)? Both ways, drop box and this, require a additional SW installed to computer, but dropbox works even when the other recipient isn't running the app. What am I missing here?

edit. Just read from the comments above that Dropbox has a web interface too. That even emphasizes my point.

The app I've used for years to do this works even without external network access. The app is basically it's own tiny web server so as long as you can get an IP address for it (just a local switch/router of any kind), it'll work. And then you can access it from any other device/computer with a web browser. You don't need to even install other software on your other things.

Exactly how useful is a file system app if you haven't jailbroken your iDevice? I mean can you actually access the device's system folders, or organize all your critical files into one folder and launch whatever program you want to view those files with?

I think this only has usefulness in the sense of geek credentials. Its practicality is dubious.

As someone who spent a lot of time trying (and failing) to move some files (family photos) to/from his iPad last weekend, this piece comes a little too late.

Still, why I need a 3rd party tool, and can't have the iPad just represent itself (or part of itself) as a thumb drive to a host OS is still puzzling.

Use the data cable to plug your iPad into a windows pc without iTunes. It shows up like plugging in a digital camera, letting you drag and drop the pictures. I've never added pics, but have moved them off using this method. This method only shows you the photo folders however.

Much easier than using my wife's Macbook, that really really wants you to use that #$%^ iPhoto app. You can even download and install the windows iCloud control panel free and set images from your iOS devices photostream to download automatically, without buying an app like Mac users are required to do.

Just tried this app out, and its pretty awesome. One of the downsides I've found so far is that there doesn't seem to be a way to put things into your camera roll on the target device. I had some video on my phone, so i added it to Air Sharing and transferred it to my iPad. It moved right over, and rather quickly. But once it was on the iPad it was stuck in the Air Sharing app. I can't seem to get it into the iPad's camera roll. I emailed Avatron support about it but i haven't heard back yet.

I like everything else this app does, though. Is there something out there specifically for copying video from the iPhone's camera roll to the iPad's camera roll without having to use a third device or iTunes?

Exactly how useful is a file system app if you haven't jailbroken your iDevice? I mean can you actually access the device's system folders, or organize all your critical files into one folder and launch whatever program you want to view those files with?

I think this only has usefulness in the sense of geek credentials. Its practicality is dubious.

I hate carrying multiple things around... why carry a thumb drive and a (supposedly) smart phone when I can just carry a smart phone to do the job of both? I've used my smartphone with this app to carry all kinds of stuff, particularly when I needed to transfer something between systems that didn't have access to the outside world. Different people have different jobs. Some of us need to carry stuff around with us or transfer stuff around. These type apps make it easy.

deet wrote:

If you have Wifi access, what are the odds you don't have Internet access?

Lots of times you do, sometimes you don't. It depends on what you're doing and where (and sometimes who you work for).

If you have Wifi access, what are the odds you don't have Internet access? Dropbox and Google Drive are free and accessible via the web with no third-party software.

This app looks like a solid execution, but its relevance is constrained by the relative complexity of its approach.

Well, considering the pathetic upload speeds of most home Internet connections, cloud storage has serious limitations. I certainly wouldn't want to pass through an external connection at 384Kbps when I could be going directly through 802.11n and Gigabit Ethernet on my LAN, particularly if I'm transferring video files that are 1-2 GB. Even my 12Mbps download speed would be pretty painful for anything over 100 MB or so. Once everyone has symmetrical gigabit Internet connections (or at least 100Mbit), cloud storage will become useful, but for now it's still painfully slow.

Personally, I use Android and just connect to my NAS over CIFS to transfer files to/from the device, basically like I do on my PCs. The only real difference is that on the PCs I typically mount the NAS folders and just access everything in-place on the NAS (unless I'm going away and need to store a copy locally on my laptop), while on the tablet I copy the files to the local device and use them there.

What I'd really like is for fast (Gigabit) symmetrical Internet connections to become the norm, so I can set up a VPN and just connect to my NAS from anywhere as if I'm on the LAN. That way I'm my own cloud storage provider.

I hate carrying multiple things around... why carry a thumb drive and a (supposedly) smart phone when I can just carry a smart phone to do the job of both? I've used my smartphone with this app to carry all kinds of stuff, particularly when I needed to transfer something between systems that didn't have access to the outside world. Different people have different jobs. Some of us need to carry stuff around with us or transfer stuff around. These type apps make it easy.

It’s a limited range of usefulness, though. If you travel to different sites fixing computers, then this could be a boon, but in what other context would it be useful? Regardless, I concede the point.

Hmm interesting. Personally I use FileBrowser app which is pretty damned awesome. That said, I also live with a good home network with a dedicated file server, a seperate USB drive hanging off the router as NAS and for on the go I have a used Sierra Overdrive hotspot that I use for its Wifi connectivity, DHCP and microSD card slot NAS ability all running SMB.

So it is super easy for me to share files around and use my iPad or iPhone as mobile storage (and you can load files up through iTunes as well over the plug if you want). Excellent UI, good speed over wireless on my network, file structures, etc and the latest update (a few months back) added the ability to unzip files as well, which has come in handy from time to time when away from a computer. Its great for streaming movies and such from my file server so that I don't have to have an iTunes server running.

About my only real complaint is it defaults to order by alphabetical, the sort doesn't seem to be able to be changed...so some of those folders can take a bit to scroll to the end to get to a file if there are several hundred in the directory. That and folders are included with all other files in alphabetical order instead of at least Windows File Explorer default of ordering folders first and then files.

I still don't understand why network filesystem deamons don't come as a standard component of the OS on iOS/Android/WinMo/whatever.

Yep, pretty lame. Especially when iOS/Android run BSD/Linux as the core and can easily include those components with no hassle. It's also crap that they don't come with OpenVPN.

Luckily, Android has plenty of FREE apps to run SSH, FTP, web servers on unpriviledged ports ... and free no-root OpenVPN for ICS. So instead of continually unplugging the cable from the power outlet to my computer, I use SSHDroid to run a server on demand and use GFTP SSH transfer mode to browsing and copy files.

Andrew Cunningham / Andrew has a B.A. in Classics from Kenyon College and has over five years of experience in IT. His work has appeared on Charge Shot!!! and AnandTech, and he records a weekly book podcast called Overdue.